I tried upgrading from v1.24 to v1.36 on WordPress 2.9.2. I can see the Notepad and I can see the configuration, but I can't edit the Notepad contents. :( The source code it's making looks like this:
<textarea id="dashboard_notepad" name="dashboard_notepad" rows="8" readonly="readonly">
Overwriting the plugin with v1.24 seemed to make it work again.